SYNCOPAL VENTRICULAR-TACHYCARDIA COMPLICA TING PAROXYSMAL ATRIAL-FIBRILLATION IN SEVERE ISCHEMIC-HEART-DISEASE

The authors report two cases of spontaneous paroxysmal atrial fibrilla tion closely followed by syncopal ventricular tachycardia resulting in cardiac arrest requiring defibrillation. Both patients, men aged 62 a nd 64 years, had a past history of myocardial infarction without arrhy thmias; atrial fibrillation occurred during severe myocardial ischaemi a; coronary arteriography showed tight stenoses of the left main coron ary artery with normal left ventricular function. Ventricular tachycar dia (or fibrillation) during spontaneous paroxysmal atrial fibrillatio n is a rare occurrence. This sequence of events has been described in patients with accessory conduction pathways or in hypertrophic cardiom yopathy. It is an exceptionally rare complication of ischemic heart di sease with only a very few previously reported cases. Myocardial ischa emia is probably the cause of the arrhythmia in together with irregula rity of the ventricular contractions responsible for long cycle-short cycle sequences which are particularly arrhythmogenic and changes in s ympathetic tone.